CHICAGO - 350,000 public school kids will return to classes Wednesday following agreement by striking teachers to end their walkout after seven days.

Teacher union delegates voted in a private meeting Tuesday to suspend the strike after considering details of a tentative contract presented over the weekend. The contract still awaits approval from the full 25,000-member union, but teachers will return to work immediately, union President Karen Lewis said.

She said the union's more than 700 delegates voted 98% to 2% to return to work.

The move heads off a confrontation with Mayor Rahm Emanuel, a former chief of staff to President Obama who on Monday tried to force an end to the strike in the nation's third largest school district. Emanuel called the agreement "an honest compromise."

The walkout had halted classes for students just after they had wrapped up summer vacation and started their academic year.

The strike focused attention on teacher complaints about evaluations and job security, echoing a larger national debate over public education, as well as pay.

Delegates leaving the meeting in their South Side union hall sang "solidarity forever."

"I'm very excited. I miss my students. I'm relieved because I think this contract was better than what they offered," said America Olmedo, who teaches fourth- and fifth-grade bilingual classes. "They tried to take everything away."

The strike drew attention to the national debate over the future of public education, including expanded use of charter schools and other elements of a reform movement opposed by teachers unions.

"This strike really shows the two opposing visions for education reform, says Kevin Kumashiro, an education professor at the University of Illinois-Chicago. The legacy left by this strike will be the role of teacher unions in the debate, he says.

"Normally, you think of unions going on strike over economic issues," such as salary and benefits, he says. But in this case, he says, the union went on strike over issues including using student achievement and test scores to evaluate teacher performance, a principal's right to select teachers and how much control a school district has to fire teachers in a failing school.

Teachers oppose using test scores to evaluate teacher performance and allow districts to get rid of a school's staff if the school underperforms.

Rick Hess, director of education at the conservative American Enterprise Institute, says the district has been pushing for changes that will pay teachers based on performance.